Wait for the other shoe to drop is an American idiom. We will examine the meaning of the idiom wait for the other shoe to drop, where it came from, and some examples of its use in sentences.
To wait for the other shoe to drop means to wait for something inevitable. For instance, a disgruntled wife may move out of her house, and her friends may wait to see if she files for divorce, or wait for the other shoe to drop. Filing for divorce is a natural next step for someone who leaves her spouse. To wait for the other shoe to drop may also mean to wait to see what someone else will do before committing oneself to a certain action or plan. For instance, a company may lay off its sales force. The rest of the employees may wait to see what the company’s next step will be, or wait for the other shoe to drop, before they decide whether to seek new employment. The phrase wait for the other shoe to drop became popular at the turn of the twentieth century, and originated in New York tenements. Tenements were usually poorly constructed, crowded apartment buildings. A resident could certainly hear his upstairs neighbor dropping his shoes on the floor as he took them off at night–first one, then the other. Related phrases are waits for the other shoe to drop, waited for the other shoe to drop, waiting for the other shoe to drop.
So one spends the benignly bland first hour of the film waiting patiently for the other shoe to drop. (The Minneapolis Star Tribune)
Often in relationships, we are waiting for the other shoe to drop. (Atwood Magazine)
“My heart is constantly pounding, just kind of waiting for the other shoe to drop,” Hudson said—meaning, she’s dreading the day her mother gets sicker and dies. (The Atlantic Magazine)
Any faltering in employment would be the other shoe to drop, given signs “of protracted weakness in investment spending, manufacturing production, and exports” that have emerged already. (Barron’s)